Effect of lesions of the basolateral am ygdala in the performance of rats treated with fluoxetine in an operational conditioning learning task

EZEQUIEL PEREYRA, SILVANO ZANUTTO

Buenos Aires

Congreso; The 2nd Congress of the Federation of Latin-American and Caribbean Societies for Neuroscience 2016; 2016

FALAN

Serotoninergic system, originated in the dorsal raphe nucleus (DRN), is one of the main regulators of the pre-frontal cortex (PFC). Basolateral amygdala (BLA) has a central role in the processing of fear and anxiety-like behaviours and mediates codification of sensory features in instrumental conditioning.The aim of this work was to study the effect of lesions in BLA in the learning of rats treated with fluoxetine, a selective serotonin reuptake inhibitor, in an operant conditioning task with an appetitive reward. Manipulations of serotonin (5-HT) levels induce different effects in the performance of diverse behavioral paradigms. In a previous study we have shown that pharmacological treatment of rats with fluoxetine improved the extinction of the task but produced a significant decrease in the performance in the adquisition phase. In the present study, 2 months old Long Evans rats were divided in four experimental groups: rats lesioned in BLA with NMDA (20mg/mL in PBS) or not and treated with fluoxetine or not. Animals were trained in Skinner boxes to reach 100% of response in the acquisition phase and until the response falls near zero in the extinction phase. We analyzed the statistical difference between treatments in the acquisition and extinction phases along the training sessions for the percentage of response and the latency. Lesions were observed by histology.Preliminary results are consistent with those found previously.